Improved saw



UNITED STATES y PATENT OFFICE.

EDWIN S. DRAKE, OF PORTLAND, MAINE.

IMPROVED SAW.

Specification forming part of LcttersPatent N0. 47,255. dated April 11,1865.

To all zrhum it may concern: p

Be it known that I, EDWIN S. DRAKE, of Portland, county of Cumberland,iu the State of Maine, have invented a new and Improved Saw; and I dohereby declare th at the following, taken in connection with thedra-wings, which accompany and form part of this specification, is adescription of Iny invention safticient to enable those skilled in theart to practice it.

In the ordinary operation of sawing7 stone, so called, it is well knownthat the process is not strictly a sawing one, but is rather a grindingoperation, being performed by reciprocation or rotation of a lap of softIne-tal supplied with some loose, hard, powdered, or granulatedsubstance-#as emery or sand, for example-and being kept from heating bya supply of Water or other suitable tiuid. This process is at best butslow and tedious, although it is the only one practiced for dividing thesofter stones-such as marble a 1d freestone-which are not laminated anddo not cleave with precision. To divide such stones into slabs with lessexpenditure of time than has heretofore been required is the object ofIny invention, which consists in a new article of manufacture, the samebeing a saw, iu the plate or body of which, or in its teeth orprojections from the body7 shall be permanzntly fixed small preciousstones of great htrduess or pieces thereofidiamonds being preferred) insuch a Inanner that said stones shall forni the cutting edges or pointsof the s tw, and so that some of them shall project 0 1 either side ofthe saw-plate, so 'as to cut a korf enough wider than the thickness ofthe sawplate to keep said plate from binding 1:1 the kerf or from cominginto contact with the solid parts of the stone undergoing the cuttingoperation.

Referring to the drawings, Figure lv is a side elevation of a sawembodying my invention, and Fig. 2 is an edge view thereof.

a denotes the plate ot' the-saw, and b the diamonds or other preciousstones which form the cutting edges or poiu ts thereof.

It will be seen on inspection of the drawings that some of the point-s bare arranged to cut the edges or side boundaries of the kerf, whileothers are arranged to cut the mid` die of it, and that there are otherswhich ext in intermediate paths, the disposition of the points b beingsuch as to cutaway all the Ina terial opposed to the progression of thesaw. To keep the points b and the plate a from heating during theperformance of the sawing operation, a stream of cold water should bekept tiowiug upon the saw where in contact with the stone.Discolorations and speck s and iiaws, which detract from the value ofdiamonds and other precious stones, do not iujure them 'for my proposeduse, and it is such cheapened stones that I propose to employ.

There is nothing new about the Inode of securing the stones in theirplaces, they being embedded in copper in a manner well known to diamondsetters, and this therefore needs no description.

I claim- As a new article of manufacture, a saw constructed with cuttingpoints or edges, substantially as described.

In witness whereof I have hereunto set my hand.

In presence ot- EDWIN S. BRAKE.

E. MCMANUS, LEVI F. BRAKE.

